Green Tea Benefits: Fact vs Fiction

More than likely, you have heard the health claims about green tea. Perhaps you have seen products containing green tea extracts on store shelves and read the claims of antioxidant benefit. You may also have read reports that green tea makers are in hot water with the FDA for making "unsubstantiated nutrition claims."

With so many things flying around, it can be difficult to decipher fact from fiction. Here is some basic information we hope will help you decide where green tea fits in your healthy beverage options.

The Claims

Some claims are general in nature such as that green tea prevents cancer, raises metabolism, or reduces cholesterol to benefit overall health. Other claims are more specific including that it stops Alzheimer's and Parkinson's diseases, treats rheumatoid arthritis, or treats impaired immune function. More and more claims are focusing on specific ailments such as that green tea helps burn fat for weight loss, cleanse the liver of toxins, assists with the prevention of type 1 diabetes, and fights a variety of cancers. Those with the risk of illness as well as those living with illness hope the claims are true. Those seeking to live health focused lives and reach weight loss goals want the claims to be true as well. But are they?

The Facts

Tea made from the Camellia sinenesis plant can be in three varieties: green, black, and oolong. Although they all have the same origin, their differences come from processing. Green tea gets all the hype for the health benefits because of its unfermented leaves that have undergone the least amount of processing. Consumed throughout Asia for generations, green tea is used for a variety of health reasons in both traditional Chinese and Indian medicine. It is typically brewed and consumed as a beverage but extracts have become very popular in the United States.

Green tea contains polyphenols as bioflavoid and catechin compounds. Among those catechins, about half are epigallocatechin gallate (EGCG for short). EGCG have strong antioxidant properties, which are about 200 times more potent than vitamin E. It is this predominant active component in the leaves of green tea that are believed to block carcinogens and free radicals that can cause cancer. There is also indication that they may exhibit antibacterial benefits that protect the digestive and respiratory systems as well.

Some studies have shown promise with green tea related to cancer. In the laboratory, tea catechins inhibited cancer growth. Unfortunately, study results in humans have been contradictory. According to the U.S. National Library of Medicine, most of the health claims for green tea have "unclear scientific evidence" related to their claims. The caffeine can initially increase alertness in those that are not used to consuming caffeine. However, over time this response will diminish as the body adjusts to the caffeine.

Nutrition Facts

A 2007 report by the United States Department of Agriculture (USDA) compared foods for catechin flavonoid content. They reported that no other beverage comes close to the catechin content in regular brewed green tea. They found that one hundred millimeters of green tea when brewed contains 126 mg of catechins while brewed oolong tea only contains 50 mg and brewed black tea only 28 mg. The report also revealed that regular green tea is the healthiest but the more processed tea becomes the more nutrients it loses. This includes the decaffeination process (56 mg) and flavoring process (43 mg), which reduces the catechin content significantly. If you are consuming instant or bottled green tea sources, most contain a disappointing 12 mg of catechins. Since Red wine contains 11 mg and unsweetened apple juice provides 6 mg, perhaps bottled or instant green tea isn't worth the cost or the hype it receives for the health benefit it offers.

Other food sources provide catechins although not as many as brewed green tea. Dark chocolate tops the list by providing 54 mg/100 grams if it is a pure Netherland source. Berries are your best nutrient rich, calorie wise option with blueberries offering 52 mg and blackberries 42 mg per 100 grams. If you love apples, be sure to eat the skin because it provides 36 mg of catechins.

There are a few other things to keep in mind when considering green tea. It contains a small amount of vitamin K, which can interfere with anticoagulants and make them less effective. Since green tea contains caffeine, it will also increase chances of insomnia, anxiety, irritability, upset stomach, nausea, diarrhea, or frequent urination in some people. Caution is indicated when taking concentrated green tea extracts especially if you have a liver disorder or experience abdominal pain after consumption.

What We Say

Green tea extract supplements are the fourth most common dietary supplement in the United States. Food is the best way to meet nutrient needs. Including a variety of food and beverage selections ensures you get everything necessary for good health. If you believe a supplement would be beneficial, it is best to seek advice from your medical provider, a pharmacist or consult a Registered Dietitian. They can help you decide about overall safety and recommend a dosage that would be beneficial as well as safe.

Brewed green tea can have a place in a healthy diet along with other coffee or tea choices. If you are looking for the greatest antioxidant health benefit, regular caffeinated brewed green tea is the form that will provide it. As with all things, moderation is important. If caffeine is a concern, remember there are other healthy foods like berries and apples with skins that provide similar antioxidant health benefits as well.

Be leery of food labeling for green tea extracts on food and beverage packages. Remember the buzz words are meant to catch your attention so that you'll buy their product and are not based on specific scientific results.

Did you know the facts about green tea or were you caught up in the marketing hype? Where does green tea fit in your healthy diet?

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Comments

Good informative article. I love tea, including green tea. I found the information regarding the absorption of iron and being careful when taking certain medications helpful. I am iron deficient and it helps to know that when I have a meal with iron I may need to wait a few hours before drinking tea. Thanks spark
- 1/10/2015 6:05:49 PM

White tea is very nice. It is picked as young buds and immature leaves then lightly processed before having time to oxidize. It is expensive but consider that by weight less white tea is used than green, oolong, or black (white tea is lighter/tablespoon) and white tea can produce multiple infusions. Good white tea can produce 3 infusions so you can use the same tea 3 times with each subsequent batch being allowed to steep longer. Silver Needle (Bai Hao Yinzhen) is the highest grade of white tea and the most expensive.
- 10/4/2010 2:04:15 PM

I find that having a cup of tea is my snack for during the day. I like green tea with lemongrass and white tea with peach. I also like Celestial Seasonings English Toffee and Peach apricot Honeybush. Before bed I sometimes have Chamomile.
- 9/26/2010 12:42:22 PM

What about ground tea leaves? A friend gave me some tea powder (not commercial instant tea) that was made by grinding green tea leaves into a very fine powder which (almost) dissolves in hot water. You do have to keep stirring it before you take a drink or some of it settles out.
- 9/25/2010 5:38:24 PM

I'm so glad this article was here. I do wish however that "white" tea had been included. I am glad to know that I can eat berries instead of caffeine since I am sensitive to it. Thanks
- 9/25/2010 1:03:07 AM

I've been drinking green tea for years. I'm sad to see that there are many on here that said they don't like the taste. That is unfortunate. I wonder if they had a 'bad batch' or a low quality brand. I've tried many different kinds of green tea and find that a few of the Japanese or Chinese loose leaf dried varieties tend to taste better than any of the packaged 'American' types. brewing time is essential, too long and it becomes bitter, too short and it doesn't have flavor or many benefits. It's a tricky art, but with practice (and possibly the advice of a Chinese brew master - which we have in Chinatown!) you can brew a lovely, light tasting cup of green tea.
- 9/24/2010 9:33:26 PM

In response to someone's question, I would like to say that I've read that the best way to prepare green tea is by using loose tea leaves, as the tea bags actually filter out some of the antioxidants. Also, if you use the tea leaves once, drain the tea and throw it out, then reuse the leaves (they still have a lot of taste left in them, I do this regularly) it takes out a great deal of the caffiene but you still get about the same antioxidant benefit. That is what I do, to avoid getting any more caffiene than necessary. For me, green tea is a great diuretic, which is something I can really benefit from.
- 9/24/2010 8:17:20 PM

I have felt guilty in the past because I don't like the taste of green tea.. I think it smells like fish. So I don't drink it, and felt I was losing out on a big benefit. However, after reading this article I'm OK with it, because I eat a variety of fruits and veggies, and probably get enough catechins though those. Thanks for such an informative article, and I will definitely save my money and not buy the flavored "green tea" drinks!
- 9/24/2010 11:58:53 AM

I did not know all these facts, especially that the decaffeinating process decreases the catechin significantly. I am not interested in consuming caffeine on a daily basis, so I won't be adding green tea to my regular diet, though I will drink it on occasion. Thank you for this information.
- 9/24/2010 11:12:07 AM

I generally consume 1-2 cups of green tea a day at work and perhaps an additional cup or two of flavored green tea. I enjoy tea as an alternative to water and was aware of the suggested benefits of green tea. I don't know if they are true but I shall continue to enjoy drinking tea no matter the findings.
- 9/24/2010 11:12:00 AM

Not a tea or coffee drinker. I have tried many teas over the years, and just don't care for it. As for coffee - let's just say that I find it bitter when it's black, and being able to put all kinds of high-calorie things in coffee just makes me glad I don't drink it. I prefer to eat my calories!
- 9/24/2010 11:03:28 AM

This was great info - I listed to a speech last week and they mentioned that the ideal temperature for brewing green tea is 180 degrees - if it is too hot it causes it to be bitter.
- 9/24/2010 10:41:51 AM

I like to drink a cup of green tea in the afternoon as pick-me-up and for the health benefits. I also drink a cup of chamomile tea at night to help me sleep, and it helps me not snack with my husband (a chronic after-dinner snacker).
- 9/24/2010 10:03:23 AM

Good, balanced information - thank you! Once a day, I have some iced green tea. It's a refreshing, satisfying beverage, and it seems to kill hunger pangs as well. But more than that, and it irritates my stomach.
- 9/24/2010 9:05:35 AM

I've been drinking green (as well as black) tea for years because I love the flavor. I always knew that drinking tea had health benefits, but I never bought into the so called hype. The fact is, eating 6-9 servings of fresh fruit and veggies has significant health benefits too.

I love tea and will continue to drink it. If it helps me add years to my life, bonus points. - 9/24/2010 8:41:51 AM

I love Green Tea and use it as a "pick me up" and because I love the flavor! China, Ireland and Eng,and all have wonderful traditions surrounding teas that goes back centuries, it comes from a beautiful plant that grows naturally from our earth...how can you go wrong with that! It is an important crop for India and if it happens to be anti-cancer ( noted for preventing NOT treating bladder cancer) I will take that additional benefit! Dr Oz and Dr Andrew Weil believe it is a food that all may benefit from and they both state that they try to drink 3 - 4 cups a day, in herbal circles for a tea to be considered "medicinal" usually at least three cups a day are recommended. Making a cup a tiea and sipping it usually has a calming effect, it is not generally something to be rushed so sip and enjoy! I do! - 9/24/2010 8:34:51 AM

I drink it daily, but I don't believe any of the HYPE. I dislike plain water, so I drink tea, YERBA MATTE tea, and Lemon water. That gets me 3 quarts daily, ,so I stay on top of my "water."
- 9/24/2010 12:43:15 AM

I love green tea, but I don't really believe it prevents cancer, as I am currently going through chemo for stage IV breast cancer. But I never drank tea expecting it to be a "miracle cure" for anything; I simply drink it because I like the taste, and it has no calories.
- 9/23/2010 5:37:43 PM

Actually, SEKMET23, Bigelow Tea does have a tea w/ omega 3s. Not green or white, though. It's part of their new Herb Plus line: Pomegranate Blueberry Herb Plus Omega 3. I tried it once. (Once was enough.) As you suspect, it wasn't a good combination at all. Yuck.
- 9/23/2010 5:12:55 PM

I can't stand green tea. I did try to drink it for a while, due to the hype, but forget it. You know, recently I saw someone selling white tea (at a fair stall) claiming that the tea had omega 3s in it. I usually ignore this type of claim because it's often wrong (tea with fat in it?!). I thought all the green tea claims were similarly suspect, if not so obviously.
- 9/23/2010 4:57:15 PM

I drink green tea daily when I can. Twice a day...early in the day is best for me. When I can't get green tea I do drink black tea also. It's good to know that there are other food sources that offer some of the same benefits as green tea. I will quit drinking the bottled tea for sure now.
- 9/23/2010 4:10:00 PM

On my trip to China I was able to visit several hospitals and pharmacies - I was struck that part of the "treatment" was brewing the ingredients into a tea. In some cases, boiling the water and increasing hydration is the best medicine, smile. My take on green tea and other things advertised as healthy is that you can't take a supplement and still continue "bad habits" expecting the supplement to counteract the other behaviors. The same way having a diet drink with a super-sized meal won't REALLY help you get to goal weight.
- 9/23/2010 3:16:27 PM

LADYSALUBRIOUS, from the little quick research I did it does seem like loose green tea will provide you the most of the health benefits. Tea in tea bags is "processed" in that it's chopped into very fine pieces. Hopefully that helps you out!
- 9/23/2010 1:08:21 PM

I decided to switch from coffee to green tea a while back because it has considerably less caffeine and coffee was keeping me up at night. I also liked my coffee with lots of cream and sugar so it drove my calories up. I new that a lot of it was hype but that it did genuinely have some benefits and it's fairly affordable especially if it's replacing your coffee. Just one more thing. Dairy kills the antioxidant benefits in all teas, so if you drink them with milk they aren't benefiting you in that way. That's the same reason why milk chocolate has no antioxidants but dark chocolate does.
- 9/23/2010 11:19:42 AM

Green tea is great at any time of day. David recommends drinking a cup with your meals to instill a sense of closure to a meal- which makes you less likely to forage the cupboards!

Recently, I bought decaf green tea to try it out. You still get the green tea extract without the added energy boost from the caffeine. I'm able to drink in late before bed and receive the same health benefits.
- 9/23/2010 10:43:52 AM

Everyday at 4pm, I have my afternoon 'tea time' where I'll make a hot cup of tea, usually herbal teas. I enjoy the Tazo tea made from rooibos which you can purchase from Starbucks or from some grocery stores.
- 9/23/2010 10:26:55 AM

@ Zucchinilovely, there is a "White Tea" Just like other teas, white tea comes from the Camellia sinensis plant. But the leaves are picked and harvested before the leaves open fully, when the buds are still covered by fine white hair. Hence the name. White tea is scarcer than the other traditional teas, and quite a bit more expensive.

White tea is similar to green tea, in that it's undergone very little processing and no fermentation. But there is a noticeable difference in taste. Most green teas have a distinctive 'grassy' taste to them, but white tea does not. The flavor is described as light, and sweet.

I love green tea and was happy to see that Lipton now has it in the Family size bags. I haven't tried the white tea but I'm willing to try it.
- 9/23/2010 9:35:55 AM

Great article. Has really opened my eyes about green tea. I'm basically a coffee drinker but a hot tea drinker in the winter months. Why, I don't know.When I do drink tea, it's green. I guess I may have gotten caught up in the hipe because the reason I started drinking gree tea is that Dr. Oz promotes 3 cups a day.
- 9/23/2010 9:32:09 AM

Freshly brewed green tea is very refreshing, and I find it gives me just the right lift. That it might also be 'healthy' is a plus that wasn't high on my radar. That bottled tea isn't (as) healthy comes as no surprise--why should it, when on other processed food is as healthy as the more naturally-produced variety?

By the way, there most certainly IS a WHITE tea: tea made with buds, and, in some cases, young leaves which are sun dried or dried by steaming. Like green tea, white tea is not oxidized.Like green, oolong and black tea, white tea comes from the Camellia sinensis plant. Oolong and black teas are oxidized before curing. That's why white, like green, can be higher in catechins than black.
- 9/23/2010 9:07:10 AM

I enjoy green tea as a beverage frequently during the week as I very much love the taste of various blends of green tea, though not after three PM as I cut out all caffeinated beverages before that time (I will drink white tea up until about six, though, as its caffeine levels are so very low). After that I switch to herbals. I drink it because it is tasty, the ritual of tea making in general is soothing to me, and it "gives me something to do" so to speak when I feel like eating just to be doing something. Since I drink it unsweetened, calories simply aren't an issue, so it's a good way of tempering the munchies.

Any health benefits I may be receiving from the drinking of green tea would therefore merely be a happy bonus and not what I seek to get out of drinking it.
- 9/23/2010 8:46:31 AM

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